I need a help about difference between Time

Question

 

 I want to get difference between dateTimePicker1 and dateTimePicker2 

 

in textbox1

 

but format textbox1= HH:mm

 

ex :  

 dateTimePicker1= 09/12/2017 | 10:00:00

dateTimePicker2 = 10/12/2017 | 11:00:00

 

 

textbox1=25:00 

 

like this pic 

  

thankyou..